466 research outputs found

    Digging Deeper into Egocentric Gaze Prediction

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    This paper digs deeper into factors that influence egocentric gaze. Instead of training deep models for this purpose in a blind manner, we propose to inspect factors that contribute to gaze guidance during daily tasks. Bottom-up saliency and optical flow are assessed versus strong spatial prior baselines. Task-specific cues such as vanishing point, manipulation point, and hand regions are analyzed as representatives of top-down information. We also look into the contribution of these factors by investigating a simple recurrent neural model for ego-centric gaze prediction. First, deep features are extracted for all input video frames. Then, a gated recurrent unit is employed to integrate information over time and to predict the next fixation. We also propose an integrated model that combines the recurrent model with several top-down and bottom-up cues. Extensive experiments over multiple datasets reveal that (1) spatial biases are strong in egocentric videos, (2) bottom-up saliency models perform poorly in predicting gaze and underperform spatial biases, (3) deep features perform better compared to traditional features, (4) as opposed to hand regions, the manipulation point is a strong influential cue for gaze prediction, (5) combining the proposed recurrent model with bottom-up cues, vanishing points and, in particular, manipulation point results in the best gaze prediction accuracy over egocentric videos, (6) the knowledge transfer works best for cases where the tasks or sequences are similar, and (7) task and activity recognition can benefit from gaze prediction. Our findings suggest that (1) there should be more emphasis on hand-object interaction and (2) the egocentric vision community should consider larger datasets including diverse stimuli and more subjects.Comment: presented at WACV 201

    Human Attention in Image Captioning: Dataset and Analysis

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    In this work, we present a novel dataset consisting of eye movements and verbal descriptions recorded synchronously over images. Using this data, we study the differences in human attention during free-viewing and image captioning tasks. We look into the relationship between human attention and language constructs during perception and sentence articulation. We also analyse attention deployment mechanisms in the top-down soft attention approach that is argued to mimic human attention in captioning tasks, and investigate whether visual saliency can help image captioning. Our study reveals that (1) human attention behaviour differs in free-viewing and image description tasks. Humans tend to fixate on a greater variety of regions under the latter task, (2) there is a strong relationship between described objects and attended objects (97%97\% of the described objects are being attended), (3) a convolutional neural network as feature encoder accounts for human-attended regions during image captioning to a great extent (around 78%78\%), (4) soft-attention mechanism differs from human attention, both spatially and temporally, and there is low correlation between caption scores and attention consistency scores. These indicate a large gap between humans and machines in regards to top-down attention, and (5) by integrating the soft attention model with image saliency, we can significantly improve the model's performance on Flickr30k and MSCOCO benchmarks. The dataset can be found at: https://github.com/SenHe/Human-Attention-in-Image-Captioning.Comment: To appear at ICCV 201

    The Behavior of Elevated Water Tanks under Impact Loading

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    Because of the crucial role of elevated water tanks and their various uses, it is necessary to evaluate their structural behavior under threats to improve the durability performance of such tanks without putting them in jeopardy. In the present research, three open cylindrical concrete water tanks were modeled under an impact load (aerial blast) with the weight of 100 kg TNT explosive charge. The tanks were modeled in 3 forms: slender, middle, and broad (Aspect ratio = 1.28,1 and 0.85). Each tank contained various levels of water (non-water, half water, and full water) to estimate their structural behavior under blast loading. Moreover, the CEL (Coupled Eulerian-Lagrangian) approach was used to simulate water structure interaction in finite element program. For a comprehensive analysis of the structural behavior of water tanks, LRB (Lead rubber bearing) isolator device was also used to observe the effect of isolator under blast loading on elevated water tanks in all models. The results of this study show that the water level leads to stiffness of the structures that cause better performance under blast loading and also the intersection of the shaft and concrete column would be the critical section of this structure under blast loading. It is also concluded that Stress and Strain decrease as the water tanks level increase and stiffen (up to 33 %). Also, it is noticeable that the existence of the isolator has deteriorated the results because of the decreases in the structure’s stiffness and the increase of the displacements

    R&D Management in Iran, Opportunities and Threats

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    Research and Development (R&D) management in Iran has faced many barriers and obstacles, in which R&D units are considered as the basic core of the product development and innovation. Due to structural shortcomings, a great number of organizations and industries have not yet been able to position themselves in the market. There are about 1141 R&D units throughout Iran, due to the geographical decentralization of these units this paper considers and analyzes the R&D case study in one of the provinces located in the north part of Iran, and the findings can be generalized to the other industrialized areas and zones in Iran. In this province, there are about 2504 industrial units of which there are only 44 R&D units certified by the state government. However, there is limited number of these R&D units that are extensively active. This paper also addresses the current status in respect with the R&D activities to find out why little attention has been paid to these activities in the industrial units. Considering the opportunities and challenges of these R&D units reveals that there is a need to activate these units so that they can quickly respond to changes in the market. Finally, a few alternative solutions and improvement plans are proposed, in which the Iranian R&D Society is responsible for supporting and fostering these action plans towards the organization goals. The research methodology was based on a previous field research conducted in Hamedan province, and after the analysis of the research results, a model for the efficiency of R&D units will be presented.R&D management, R&D Society, Innovation, Industrial sectors

    Wideband Directional Coupler for Millimeter Wave Application based on Substrate Integrated Waveguide

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    Recently, Substrate Integrated Waveguide (SIW) techniques have been noticed for millimeter wave devices in microwave applications. In this paper, we are developing a wide band directional 3 dB coupler with a phase of 90̊ phase delay in the range of 30-40 GHz based on periodic vias and multi hole structure. For achieving this wide bandwidth multi-section coupler is designed based on the theoretical modeling and the simulation result is compared with HFSS and CST with  two different  numerical  methods show good performance with low insertion and return loss, broad operational bandwidth and high isolation. A fractional bandwidth is about 28.5 %
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